1. The Field of the Invention
This invention is in the field of methods and devices for mixing and dispensing compositions. More particularly, this application is directed to methods and devices for mixing and dispensing multi-part medical and dental compositions.
2. The Relevant Technology
Adaptors have been employed in the art in order to couple one syringe in fluid communication with another syringe. Such adaptors are typically configured to be positioned between the syringes by coupling one portion of the adaptor to one syringe and another portion of the adaptor to another syringe. Typical adaptors have a passageway therethrough in order to enable material in one syringe to pass through the passageway of the adaptor to the opposing syringe. After coupling the adaptor between opposing syringes, material from one syringe may be delivered through the adaptor into another syringe.
A variety of different uses for such so-called "syringe-to-syringe adaptors" are available. For example, syringe-to-syringe adaptors may be useful for connecting a large reservoir syringe to the small dose syringe so that the material stored in the large reservoir syringe may be transferred to a small dose syringe. Syringe-to-syringe adaptors may also be used for back-filling a syringe or for combining materials in different syringes to form a mixture.
First and second syringes may also be coupled directly together without the use of an adaptor therebetween in order to combine materials disposed within the syringes. The plungers of the syringes are alternatively compressed or actuated in cycles until the materials within the syringes mix.
There are many advantages to typical syringe-to-syringe mixing applications, both with respect to applications involving syringes which directly couple in order to combine material and with respect to syringes which couple through the use of an adaptor. However, each of such typical syringe-to-syringe mixing applications feature a single, linear pathway which extends from one syringe to another or from one end of an adaptor to an opposing end of the adaptor.
Consequently, material in the distal tip portion of a first syringe is delivered in a substantially linear manner through the linear pathway to the distal tip portion of a second syringe. If the plunger of the second syringe is then pressed, substantially the same material delivered to the tip of the second syringe is delivered back along the same linear pathway in an opposite direction. As a result, substantially the same material originally delivered from the distal tip of the first syringe is returned back to the distal tip of the first syringe.
Thus, material located remotely from the tips can remain in such a remote position and fail to mix. Instead, substantially the same material is pushed back and forth along the linear pathway between the tips of the syringes. Overall, this phenomenon can result in inadequate mixing of the components from one syringe to another or can require long mixing times in order to mix the components.
Another problem within the art relates to the expense and inconvenience of using removable caps to cover syringes containing materials to be mixed. Before mixing materials in first and second syringes, the syringes must typically be opened, i.e., by removing removable caps on each syringe. This technique is time consuming and requires the production of caps which can be removed from the syringes.